Interface Level

Solaris DDI specific (Solaris DDI).

Description

The arguments s, s1, and s2 point to strings (arrays of characters
terminated by a null character). The strcat(), strncat(), strlcat(), strcpy(), strncpy(), strlcpy(),
and strfree() functions all alter their first argument. Additionally, the strcpy() function
does not check for overflow of the array.

strcasecmp(), strncasecmp()

The strcasecmp() and strncasecmp() functions are case-insensitive versions of strcmp() and
strncmp() respectively, described below. They assume the ASCII character set and
ignore differences in case when comparing lower and upper case characters.

strncat(), strlcat()

The strncat() function appends at most n characters of string s2, including
the terminating null character, to the end of string s1. It returns
a pointer to the null-terminated result. The initial character of s2 overrides
the null character at the end of s1. If copying takes place
between objects that overlap, the behavior of strncat()and strlcat() is undefined.

The strlcat() function appends at most (dstsize-strlen(dst)-1) characters of src
to dst (dstsize being the size of the string buffer
dst). If the string pointed to by dst contains a null-terminated string
that fits into dstsize bytes when strlcat() is called, the string pointed
to by dst will be a null-terminated string that fits in dstsize bytes
(including the terminating null character) when it completes, and the initial character
of src will override the null character at the end of
dst. If the string pointed to by dst is longer than dstsize bytes
when strlcat() is called, the string pointed to by dst will not
be changed. The function returns min{dstsize,strlen(dst)}+strlen(src). Buffer overflow can be checked as
follows:

if (strlcat(dst, src, dstsize) >= dstsize)
return -1;

strchr(), strrchr()

The strchr() function returns a pointer to the first occurrence of c
(converted to a char) in string s, or a null pointer
if c does not occur in the string. The strrchr() function returns a
pointer to the last occurrence of c. The null character terminating a
string is considered to be part of the string.

strcmp(), strncmp()

The strcmp() function compares two strings byte-by-byte, according to the ordering of
your machine's character set. The function returns an integer greater than,
equal to, or less than 0, if the string pointed to
by s1 is greater than, equal to, or less than the string pointed
to by s2 respectively. The sign of a non-zero return value is
determined by the sign of the difference between the values of
the first pair of bytes that differ in the strings being compared.
The strncmp() function makes the same comparison but looks at a maximum of
n bytes. Bytes following a null byte are not compared.

strcpy(), strncpy(), strlcpy()

The strcpy() function copies string s2 to s1, including the terminating null
character, stopping after the null character has been copied. The strncpy() function
copies exactly n bytes, truncating s2 or adding null characters to s1 if
necessary. The result will not be null-terminated if the length of s2
is n or more. Each function returns s1. If copying takes
place between objects that overlap, the behavior of strcpy(), strncpy(), and strlcpy() is
undefined.

The strlcpy() function copies at most dstsize-1 characters (dstsize being the
size of the string buffer dst) from src to dst,
truncating src if necessary. The result is always null-terminated.
The function returns strlen(src). Buffer overflow can be checked as follows:

if (strlcpy(dst, src, dstsize) >= dstsize)
return -1;

strfree()

The strfree() function frees the memory associated with the string pointed to
by s. This memory pointed to by s must be of
size strlen(s)+1, and must have been allocated (either directly or indirectly) by kmem_alloc(9F)
or kmem_zalloc(9F).

strspn()

The strspn() function returns the length of the initial segment of string
s1 that consists entirely of characters from string s2.

strdup(), ddi_strdup()

The ddi_strdup() function returns a pointer to a new string that is
a duplicate of the string pointed to by s1. The returned pointer
can be passed to strfree() or kmem_free(9F). The space for the new
string is obtained using kmem_alloc(). flag can be either KM_SLEEP or KM_NOSLEEP,
and determines whether the caller can sleep for memory. KM_SLEEP allocations may sleep
but are guaranteed to succeed. KM_NOSLEEP allocations are guaranteed not to sleep
but may fail (return NULL) if no memory is currently available.

The strdup() function behaves the same as the ddi_strdup() when called with
the KM_SLEEP flag. This means that strdup() can sleep until memory is
available and will always succeed.

strlen(), strnlen()

The strlen() function returns the number of bytes in s, not including
the terminating null character.

The strnlen() function returns the smaller of n or the number of
bytes in s, not including the terminating null character. The strnlen() function
never examines more than n bytes of the string pointed to by s.

strstr()

The strcasestr() function locates the first occurrence of the string s2 (excluding
the terminating null character) in string s1 and returns a pointer to
the located string, or a null pointer if the string is not
found. If s2 points to a string with zero length (that is,
the string “”), the function returns s1.

strcasestr()

The strcasecmp() function is a case-insensitive version of strstr(). It assumes the
ASCII character set and ignores differences in case when comparing lower and
upper case characters.

Context

The strdup() and ddi_strdup() functions can be called from user or kernel
context.

The ddi_strdup() function can be called from interrupt context only if the
KM_NOSLEEP flag is set.

All the other string manipulation functions can be called from user, interrupt,
or kernel context.